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Services  /  Dam Break & River Flood Modelling
Service 08

Dam Break & River
Flood Modelling.

Specialist simulation of dam breach scenarios and extreme river flooding events — predicting downstream inundation for emergency planning, dam safety compliance, and infrastructure risk assessment.

Dam breach modellingFlood wave propagationHEC-RAS breachEmergency planningRP100–RP100014–28 days
At a glance
14–28 days
Standard delivery
RP1000
Max return period
Breach
Specialist capability
Every study includes
  • Dam breach scenario modelling — overtopping, piping, structural
  • Downstream flood wave propagation & arrival time mapping
  • Inundation depth, velocity & hazard zone mapping
  • Emergency planning & evacuation route analysis
  • Named engineer · Post-delivery support
HEC-RAS breach
Primary tool
RP100–1000
Return periods
Arrival times
Key output
Emergency zones
Mapped output
What it is

Dam Break & River Flood Modelling — what HYDRisk delivers.

Dam break and river flood modelling addresses the highest-consequence flood scenarios — events that, if not planned for, can result in catastrophic downstream damage and loss of life. This specialist modelling service covers dam breach analysis, extreme river flood routing, and the downstream consequences of structural failure or extreme rainfall events.

HYDRisk dam breach models simulate three primary failure mechanisms: overtopping (where flood water exceeds the dam crest), internal erosion/piping (where seepage causes progressive failure), and structural failure (instantaneous collapse). Each produces a different breach hydrograph and downstream flood wave.

The downstream hydraulic model traces the flood wave from the breach point to all infrastructure, settlements and critical facilities downstream — producing depth, velocity, hazard and arrival time maps at every location.

All HYDRisk dam safety studies are documented to the standard required by regulatory bodies across the United States, Europe, the Middle East and internationally — with full model transparency and calibration documentation.

Why dam break modelling matters
“A dam that fails without warning downstream communities is not just an engineering failure — it is a catastrophic, preventable disaster.”
Three breach mechanisms modelled explicitly
Full downstream flood wave tracing
Arrival time maps for emergency response
Regulator-ready documentation
Why it matters

Four reasons this service is critical to your project.

Understanding what this study delivers — and what happens without it — is the fastest way to evaluate whether your project needs it.

Dam safety regulations increasingly require breach analysis
National dam safety guidelines require quantitative flood wave analysis for dams above a specified size. A dam without an up-to-date breach analysis may not retain regulatory approval.
Downstream infrastructure risk needs quantified depths and velocities
Roads, bridges, pipelines and settlements downstream of a dam face risks only quantifiable through hydraulic modelling — essential for insurance and emergency planning.
Emergency response needs flood wave arrival times
Effective evacuation requires knowing when the flood wave arrives at each location — not just its depth. Modelling produces arrival time maps for real response planning.
Extreme events beyond design floods must still be assessed
Standard design floods stop at RP100 or RP200. Dam safety practice requires assessment out to RP1000 and Probable Maximum Flood conditions.
What we deliver

Specific deliverables — not vague promises.

Every HYDRisk study produces a defined set of technical outputs — here is exactly what you receive.

Technical modelling outputs
  • Dam breach hydrograph — overtopping, piping, structural failure
  • Downstream flood routing — HEC-RAS 1D/2D unsteady flow simulation
  • Peak flood depth and velocity maps at all downstream locations
  • Flood wave arrival time maps — for emergency planning
  • Inundation hazard classification — downstream of breach point
  • Extreme river flood modelling — RP100, RP200, RP500, RP1000
Report & GIS deliverables
  • Dam safety report — breach analysis, model results, compliance
  • Flood inundation maps — breach and extreme scenarios in GIS format
  • Flood wave arrival time map — for emergency response planning
  • Infrastructure risk assessment — depth and velocity at downstream assets
  • Emergency planning zone map — based on modelling outputs
  • Evacuation route assessment — serviceability under flood conditions
Regulatory documentation: All studies documented to national dam safety standards. Model files delivered with calibration documentation. Emergency planning outputs formatted for civil defence and disaster management authorities.
Request a scope →
Tools & methodology

Industry-standard tools. Region-specific data.

Every tool we use is the same software trusted by government agencies, major engineering firms and regulatory bodies worldwide.

HEC-RAS (breach)
US Army Corps of Engineers
Unsteady flow with dam breach module. Industry-standard tool for dam safety analysis, breach simulation and downstream routing.
Breach simulationFlood routing
HEC-HMS
US Army Corps of Engineers
Hydrological modelling for inflow flood hydrograph generation — the upstream boundary condition for dam safety analysis.
Inflow hydrologyPMF analysis
QGIS / ArcGIS
Open Source / Esri
GIS mapping of downstream flood hazard, arrival times, infrastructure risk and emergency planning zones.
Hazard mappingEmergency zones

Step-by-step methodology

Step 01
Data collection
Dam geometry, spillway capacity, freeboard, downstream DEM, infrastructure mapping, historical flood records.
Step 02
Inflow hydrology
Probable Maximum Flood estimation and design inflow hydrographs for RP100, RP500, RP1000. HEC-HMS modelling.
Step 03
Breach parameter estimation
Breach width, side slope, and formation time estimated from empirical relationships calibrated to dam type and size.
Step 04
Breach simulation
HEC-RAS unsteady flow with breach module. Three failure scenarios: overtopping, piping, structural.
Step 05
Downstream flood routing
Flood wave routed downstream to all locations of interest. Depth, velocity and arrival time extracted at each location.
Step 06
Emergency planning outputs
Flood hazard and arrival time maps. Infrastructure risk assessment. Emergency planning zone designation and reporting.
Regional applicability

Calibrated for your region and regulatory framework.

Methodology, data sources and regulatory requirements differ between geographies. HYDRisk delivers the right approach for every region.

United States — Primary market
FEMA & state dam safety
FEMA dam safety guidelines, state dam safety office compliance, NOAA/USGS data.
Regulatory frameworks
FEMA dam safetyState dam safety offices
  • FEMA dam safety guideline compliance
  • State dam safety office coordination
  • NOAA/USGS data for inflow hydrology
Middle East & GCC
GCC-specific methodology
Wadi dam breach analysis, arid-region inflow hydrology, GCC dam safety compliance.
Regulatory frameworks
UAE MunicipalityAshghal (Qatar)
  • Wadi dam breach flood routing methodology
  • Arid-region PMF and inflow hydrology
  • UAE, Saudi Arabia, Qatar dam safety compliance
International
Global dam safety methodology
ICOLD guidelines, IFC PS4 compliance, ERA5/CMIP6 for future inflow analysis.
Regulatory frameworks
ICOLD guidelinesIFC PS4
  • ICOLD international dam safety guideline alignment
  • IFC PS4 dam safety and emergency planning compliance
  • Remote delivery — any geography covered
Related services

Services often commissioned alongside this study.

Service 03
Hydraulic Modelling
Downstream river routing for dam breach scenarios uses the same 1D/2D hydraulic modelling tools as a standard river flood study.
View service →
Service 04
Hydrological Studies
Inflow hydrology — peak discharge and PMF estimation — is the upstream boundary condition for all dam safety hydraulic analysis.
View service →
Service 09
Flood Mitigation
Downstream flood protection design in response to dam breach risk — embankments, warning systems and evacuation infrastructure.
View service →

Ready to commission a dam break flood study?

Tell us your dam type, size, and downstream context. We will scope the study and have a fixed-fee proposal within 24 hours.

Get a free consultation →
Proposal within 24hFixed-fee pricingNo obligation